Julian Assange's lawyer revealed in a video message on Saturday that he and his partner - a former member of his legal team - had two children together, while he lived in the Ecuadorian embassy in London.
The children are 3-year-old Gabriel and 1-year-old Max.
The Wikileaks founder is currently in Belmarsh prison waiting to see if he will be extradited to the United States over espionage charges.
In a video posted to YouTube, Assange's partner, Stella Morris, said the couple are engaged, and showed videos of their alleged children.
Morris called for Assange's release amid coronavirus concerns.
"I feel now that I have to do this, because I've taken so many steps for so many years and I feel like Julian's life might be coming to an end," she said tearfully in the video.
"I don't think people understand the extreme situation and pressure that we've been under because Julian is a public figure," she said.
Morris says the couple met in 2011 and got together in 2015.
Another lawyer for Assange, Jennifer Robinson, confirmed to AFP that Morris and Assange were a couple. She said that Morris had previously made a statement in court on his behalf.